Shuttles



March 23, 1965 H. scHFFER 3,174,514

sHUTTLEs Filed June 20, 1962 Q 782 @4 1 Ngs ATTORNEYS United States Patent 3,174,514 SHUTTLES Heinrich Schffer, Werther, near Bielefeld, Germany, asiignor to C. A. Delius Sahne, Bielefeld, Germany, a rm Filed .lune 20, 1962, Ser. No. 203,774 Claims priority, application Germany, .lune 23, 1%1, D 36,393 l5 Claims. (Cl. 139-125) The invention relates to shuttles without bobbins. Shuttles of this type are used in looms for inserting weft threads trom one or both sides of the `web into the shed, said threads being drawn oli tixed spools and then often measured before insertion.

Various `constructions .of bobbin-free shuttles are known, namely the `so-called carrie-r shuttles, which grip a previously drawn out loop of thread in its middle portion by means of a carrier element and insert it into this thread, yand .the so-called gripper shuttles, which grip the end of a previously measured loopof thread lor the end of the thread on a reserve bobbin by means of a clamp, and carry the weft thread into the shed.

If the weft thread is inserted in the form of a loop by means of the known bobbin-free carrier shuttles, the speed of the Vfree end of the rweft thread to be inserted increases to twice the speed of the shuttle owing to the dfiection of the weft thread on the carrier. When delicate weft material is used, .for example artificial silk, this may cause a slight stretching of the weft threads. A further disadvant-age of the carrier shuttles consists in that the free end of the weft thread, which iiutters freely in the shed, -rnay get clamped between the shuttle and the reed or between the shuttle and the sley during the insertion ot' the weft thread. This cau-ses an increase in tens-ion when the weft thread leaves the shuttle, so that the weft thread tends to jump back into the shed. Moreover, this uncontrollable freely movable end of the weft thread easily becomes entangled .and forms loops, thereby leading to obstructions during .the insertion of the weft thread.

When the weft thread is Iinserted as `a loop by means of gripper shuttles, the release of the end of the weft thread always gives rise to great diiculties. The reason for this lies in the `fact that when the thread is inserted by this method, the clamp situated in the shuttle must be actuated during the ight of the shuttle, because the end of the weft thread cannot be pulled back to the edge of the web. It is hardly possible rfor this actuation to be effected without disturbances if the shuttle moves at high velocities. A further disadvantage of the gripper shuttles is that their movable parts are subject to excessive lwear owing to the great accelerations of the shuttle. A -further disadvantage is that the shuttles must always take up the same position in the shuttle box for the takeup of the thread, and it is .almost always necessary to provide special apparatus for this purpose, which trequently give rise to disturbances.

It is the aim of the invention to provide a bobbin-free shuttle for inserting weft threads of previously measured length, in which the above disadvantages .are avoided.

To solve this problem, the invention provides a .bobbin free shuttle ywhich is provided, as already known for gripper shuttles, with a longitudinal slot and with retaining and brak-ing means lfor pulling through and taking up the end of ya weft thread, and this shuttle is substantially characterised by the .fact that the longitudinal slot extends from the middle of the shuttle toward but terminates short of, the tips of the shuttle, that the longitudinal slot extends over the whole width or height of the shuttle, and that one or two retaining and braking means which are provided with retaining .and braking elements bearing against one of the lateral surfaces of the longitudinal 3,174,514 Patented Mar. 23, 1965 slot is or are arranged in the longitudinal slot, in the middle or at both ends thereof. In this construction of the shuttle, the end of the weft thread which is to be inserted may easily be pushed or blown through the longitudinal slot of the shuttle by mechanical or pneumatic means. Moreover, ,with a 4shuttle constructed as above, the end of the weft .thread is gripped and held during the movement of the shuttle thro-ugh the shed, owing toy the presence of the retaining and braking elements. Finally, the retaining and braking elements make it possible tor the end :of the wet thread to slide off the shuttle Wt-ihout 'any considerable resistance, when the shuttle has reached the end of its movement through the shed.

Further, according to the invention, the longitudinal slot of this novel shuttle is provided with one or two enlargements .in the region used for carrying the end of the weft thread through. These enlargements facilitate the process of inserting or blowing the end of the weft thread through the shuttle.

Accor-ding to a further lfeature of the invention, a thread guiding groove is providedl adjacent to e-ach end of the longitudinal sl-ot of the shuttle, at the side of the shuttle facing the .free portion of the end of the weft thread, each groove extending to the corresponding tip of the shuttle. The free portion of the end of the weft thread is taken up by these thread guide grooves during the movement of the shuttle through the shed, the end of the thread being thereby protected against undesirable influences which could have a braking or clamping eltect on it.

According to a preferred embodiment of the new shuttle, the invention provides that the retaining and braking means are each formed by a bundle of braking elements in the vtorrn of bristles, the bristles being arranged on one of the lateral surfaces of the longitudinal slot, inclined in the direction of the associated tip or middle of the shuttle, and bent yat the top ends, the said bristlesV being in resilient engagement with the other lateral surface of the longitudinal slot. In this constructie-nal embodiment, the end of the weft thread cornes to lie, during the movement of the shuttle, between the upper ends of the bristles of the bundle and the lateral surface of the. longitudinal slot situated opposite the bundle, .and is held there due to the resilient engagement between the bristles of the bundle 4and the said lateral surface :of the longitudinal slot until, at the end of the movement of the shuttle through the shed, it slides off the shuttle, then bristles of the bundle exerting a certain braking effect at this stage.

In the said embodiment, the invention further provides that the width or thickness, or density, of the bundle of bristles or the elasticity of the bristles diminishes from the middle of the shuttle to the tip thereof or converse ly, whereby a corresponding reduction in the contact presl sure exerted on the weft thread by the bundle of bristles results. This has the advantage that the braking effect produced by the bristles on the end of the weft thread when the latter .slides from the shuttle is steadily reduced, and consequently the end of the weft thread can be transl ferred to suction elements introduced into the shed withl out the said thread jumping back into the shed.

According to a furt er feature of the invention, recesses tor receiving the bundle of bristles are provided in the above described constructional embodiment of the new shuttle, these recesses being situated within one of the lateral surfaces of the longitudinal slot. With this construction, the bundle ot' bristles may easily be inserted and removed for cleaning purposes or other purposes.

ln all the consti-notional embodiments of the new shuttle according to the invention, the part or surface of which deiines the side of the longitudinal slot against which the retaining and braking elements act may be formed by -a detachable insert plate. This plate is preferably made of transparent material. This feature facilitates the insertion and removal of the retaining and braking means as well as their adjustment. It further makes it possible to keep the retaining and braking elements under observation and to observe any blockages occurring in the latter and in the longitudinal slot.

Apart from the above mentioned advantages, the bobbin-free shuttle has the advantage over the known types of bobbin-free shuttles that it conta-ins no movable or projecting parts `such as entrainment elements or the like. There is the further advantage that the shuttle need not take up any particular position in the shuttle box for the insertion and uptake of the end of the weft thread; this feature results in a considerable increase in the safety and reliability of the operation. As the new bobbin-free weaving shuttle need not contain any metal parts apart from its tips, its weight may advantageously be reduced, and this also has a favourable effect on the weaving operation. Owing to its smooth and closed outer surfaces and to its light weight, the new bobbin-free shuttle is particularly suitable for being driven by friction rollers instead of the usual beating devices. Finally, the new shuttle is particularly suitable for use in weaving looms in which the end of the weft thread is taken up and smoothed out by suction elements in the shed as it slides off the shuttle at the end of the weft thread insertion.

The preferred embodiment of the new bobbin-free shuttle has been illustrated by way of example in the accompanying drawing.

FIGURE l is an exploded perspective view of a shuttle constructed in accordance with one embodiment of the invention;

FIGURE 2 is a top plan view of the shuttle shown in f FIGURE l;

FIGURE 3 is a longitudinal section through the shuttle, taken on the line 3-3 of FIGURE 2;

FIGURE 4 is a transverse section taken on the line 4--4 of FIGURE 3;

FIGURE 5 is a top plan view of a slightly modified shuttle;

FIGURE 6 is a longitudinal section taken on line 6-6 of FIGURE 5; and

FIGURE 7 is a top plan View of a rnodied form of retaining and braking means having the retaining and braking elements diminishing in thickness, or density, from one end of the retaining and braking means to the other.

The shuttle shown in the drawing is relatively at in construction and has a longitudinal slot 1 extending over its whole width and from the middle toward, but terminating short of, the two tips. The longitudinal slot 1 is situated in the upper part of the shuttle, land in the middle of the shuttle it has a downwardly directed enlargement 2 which extends over a part of its length. Adjacent to the longitudinal slot 1, the shuttle is provided on one side with thread guiding grooves 3 which extend to the tips of the shuttle.

Retaining and braking means 4 are arranged in the shuttle adjacent to the central enlargement 2 of the longitudinal slot 1. Retaining and braking means 4 are formed by plates 6 containing bundles of resilient bristles 5. The lower surface of the longitudinal slot 1 is provided with recesses 7 to seat the retaining and braking means 4. Apertures 8 are provided on the undersurface of the shuttle for the insertion and removal of the bundles of bristles 5.

The bristles S are inclined at an angle to the plates 6 on which they are mounted, and are bent at the tips. The bristles 5 are inclined to the associated tip of the shuttle and the curved ends of the bristles point in the same direction. The width over which the bristles 5 are arranged on the plates 6 diminishes from the middle of the shuttle to the tips of the shuttle in the form of a trapezium. Y

Within the shuttle, the upper ends of the bristles 5 are in resilient engagement with the upper surface of the slot 1. This resilient engagement as well as the recesses 7 hold the bundles of bristles 5 securely in the shuttles without any additional securing means being required.

While the shuttle is at rest in the shuttle box, the free end 9 of a measured length of weft thread withdrawn from a bobbin is inserted by mechanical or pneumatic means through the portion of the longitudinal slot 1 which has the enlargement 2, and takes up the position indicated by the reference a in FIGURE 2. When the shuttle is then set in motion to insert the weft thread into the shed, the end 9 of the weft thread takes up the position shown in broken lines and indicated by the reference b in FIG- URE 2, in which it lies between the rear bundle of bristles situated near the middle of the shuttle, and the upper surface of the slot 1, and is taken up partly by the slot 1 and partly by the adjacent guiding groove 3. Only the outermost part of the end 9 of the weft thread then extends slightly beyond the rear tip of the shuttle. Owing to the contact pressure exerted by the corresponding bundle of bristles, the end 9 of the weft thread is held in this position during the greater part of the shuttle movement. Any clamping or looping of the end 9 of the weft thread is thereby prevented.

The end 9 of the weft thread then slides off the shuttle at the end of the movement of the shuttle through the shed. In this process, the end of the weft thread gradually moves from the end of the bundle of bristles 5 close to the middle of the shuttle to the end of the bundle near the tip of the shuttle, the thread thereby moving through the positions shown in broken lines in FIGURE 2 and indicated by the references c, and d. Owing to the fact that the bristle bundle tapers towards the rear tip of the shuttle, the braking action exerted by the bristles 5 on the end 9 of the weft thread gradually diminishes and is finally reduced to a fairly low value. The end 9 of the weft thread can therefore slide completely off the shuttle without any effective braking resistance from the bristles 5, and can be taken over by the suction elements (not shown) which enter the shed, and be smoothed out by them.

The top of the shuttle contains a removable insert plate i 16 of transparent material located over the recesses 7.

It is this plate that the bristles S bear upon, and the transparency of the plate makes it possible to keep the bristles in view to check their position and action.

In FIGURES 5 and 6, the shuttle 11 has a slot 12 and thread grooves 13. In this form, the slot is enlarged at both ends, as at 14, rather than in the middle. A single recess 15 is located centrally of the shuttle to receive retaining and braking means 16 having bundles 17 of bristles 18. The bundles taper toward the center and the bristles are inclined toward the center of the shuttle. A plate 19 overlies the bristles. In this case, the thread is inserted through the enlargements 14 and is pulled toward the center. The braking effect of the bristles diminishes toward the center to release the thread.

In FIGURE 7, a single retaining and braking means 20 is shown. In this form of the invention, the plate 21 carries a rectangular bundle of bristles 22, but the thickness, or density, of placement of the bristles diminishes from one end of the bundle to the other, from right to left as shown. This will result in diminishing holding power as before.

I claim:

l. A bobbin-free gripper shuttle having a central portion and tips with a longitudinal slot and retaining and raking means for retaining ends of weft thread, characterized in that the longitudinal slot extends completely through the shuttle along the central portion and terminates short of the tips, and the retaining and braking means are within the longitudinal slot and are provided with retaining and braking elements which are inclined toward a tip of the shuttle and bear against one of the surfaces of the shuttle deiining a side of the longitudinal slot.

2. A bobbin-free gripper shuttle having a central portion and tips with a longitudinal slot and retaining and braking means for retaining ends of weft thread, characterized in that the longitudinal slot extends completely through the shuttle along the central portion and terminates short of the tips and is provided with an enlargement to permit the free entry of ends of weft threads, and that retaining and braking means are provided in the longitudinal slot at each end of the slot, the said retaining and braking means being provided with retaining and braking elements which bear against one of the surfaces of the shuttle defining a side of the longitudinal slot.

3. A bobbin-free gripper shuttle having a central portion and tips with a longitudinal slot and retaining and braking means for retaining ends of weft thread, characterized in that the longitudinal slot extends completely through the shuttle along the central portion and terminates short of the tips, and that retaining and braking means are provided in the longitudinal slot at each end of the slot, the said retaining and braking means being provided with retaining and braking elements which are bristles inclined in the direction of the shuttle tips to which they are adjacent, the ends of the bristles being bent and in resilient contact with one of the surfaces of the shuttle defining a side of the longitudinal slot.

4. A bobbin-free gripper shuttle according to claim 3, wherein the bristles are arranged in bundles which diminish in width in a direction from the center of the shuttle toward the tip.

5. A bobbin-free gripper shuttle according to claim 3, wherein the bristles are arranged in bundles which diminish in thickness in a direction from the center of the shuttle toward a tip.

6. A bobbin-free gripper shuttle according to claim 3, wherein the bristles are arranged in bundles in which the elasticity of the bristles of each bundle diminishes in a direction from the center of the shuttle toward a tip.

7. A bobbin-free gripper shuttle according to claim 3, wherein the surface of the shuttle defining a side of the longitudinal slot opposite that against which the bristles are in resilient contact is recessed to seat the retaining and braking means.

8. A bobbin-free gripper shuttle having a central portion and tips with a longitudinal slot and retaining and braking means for retaining ends of weft thread, characterized in that the longitudinal slot extends completely through the shuttle along the central portion and terminates short of the tips and is provided with two enlargements to permit free entry of ends of weft threads, and the retaining and braking means are provided in the longitudinal slot at the middle thereof, the said retaining and braking means being provided with retaining and braking elements which bear against one of the surfaces of the shuttle defining a side of the longitudinal slot.

9. A bobbin-free gripper shuttle having a central portion and tips with a longitudinal slot and retaining and braking means for retaining ends of weft thread, characterized in that the longitudinal slot extends completely through hte shuttle along the central portion and terminates short of the tips, and the retaining and braking means are provided in the longitudinal slot at the middle thereof, the said retaining and braking means being provided with retaining and braking elements which are bristles inclined toward the center of the shuttle, the ends of the bristles being bent and in resilient contact with one of the surafces of the shuttle dening a side of the longitudinal slot.

10. A bobbin-free gripper shuttle according to claim 9, wherein the bristles are arranged as a bundle of bristles which diminishes in width in directions from the tips of the shuttle toward the center of the shuttle.

11. A bobbin-free gripper shuttle according to claim 9, wherein the bristles are arranged as a bundle of bristles which diminishes in thickness in a direction from the tips of the shuttle toward the center of the shuttle.

12. A bobbin-free gripper shuttle according to claim 9, wherein the bristles are arranged as a bundle of bristles having elasticity which diminishes in a direction from the tips of the shuttle to the center of the shuttle.

13. A bobbin-free gripper shuttle according to claim 9, wherein the surface of the shuttle defining a side of the longitudinal slot opposite that against which the bristles are in resilient contact is recessed to seat the retaining and braking means.

14. A bobbin-free gripper shuttle comprising, a central shuttle portion generally rectangular in transverse cross-section and tips projecting from the opposite ends of the central portion, the central portion having a slot extending longitudinally the full length thereof and horizontally completely therethrough providing a passage through the shuttle for ends of weft threads, and retaining and braking means within the horizontal slot having retaining and braking elements which bear against one of the surfaces of the shuttle deiining a side of the slot.

15. A bobbin-free gripper shuttle as claimed in claim 14 wherein, there are grooves on one side of the shuttle from the ends of the slot in the central portion along the tips.

References Cited in the file of this patent UNITED STATES PATENTS 948,945 Smith Feb. 8, 1910 1,215,729 Smith Feb. 13, 1917 2,072,160 Dewas Mar. 2, 1937 FOREIGN PATENTS 1,260,531 France Mar. 27, 1961 

1. A BOBBIN-FREE GRIPPER SHUTTLE HAVING A CENTRAL PORTION AND TIPS WITH A LONGITUDINAL SLOT AND RETAINING AND RAKING MEANS FOR RETAINING ENDS OF WEFT THREAD, CHARACTERIZED IN THAT THE LONGITUDINAL SLOT EXTENDS COMPLETELY THROUGH THE SHUTTLE ALONG THE CENTRAL PORTION AND TERMINATES SHORT OF THE TIPS, AND THE RETAINING AND BRAKING MEANS ARE WITHIN THE LONGITUDINAL SLOT AND ARE PROVIDED WITH RETAINING AND BRAKING ELEMENTS WHICH ARE INCLINED TOWARD A TIP OF THE SHUTTLE AND BEAR AGAINST ONE OF THE SURFACES OF THE SHUTTLE DEFINING A SIDE OF THE LONGITUDINAL SLOT. 